Inhalers for medicament delivery are well known and very widely used, especially—but by no means exclusively—in the treatment of asthma and of chronic obstructive pulmonary disease. In a metered-dose type inhaler (“MDI”), a replaceable canister containing the active agent is pressurised with a propellant and is provided with a metering valve which dispenses a controlled dose of the active agent (hereinafter referred to simply as a “dose”) each time it is activated. The inhaler canister is carried in a housing which is typically a moulded plastics item which has a body for receiving the canister as an interference fit, and a mouthpiece. The housing is roughly “L” shaped in side view so that the user can place his/her lips around the mouthpiece, which extends roughly horizontally, whilst the housing's body and the inhaler canister are generally upright.
The metering valve is typically activated by manual action on the part of the user. For example the user may be required to press on an exposed end of the canister to slide it a short distance into the body. This action applies pressure to a nozzle end of the canister to activate its metering valve and cause release of a dose. At the same time the user inhales so that the dose is drawn into the lungs along with a volume of air. The housing is open to the exterior to admit this volume of inhaled air. Typically the flow path for the air passes through a space in the housing body around the inhaler canister.
Many users need to carry an inhaler with them routinely. Asthma sufferers, for example, may need to keep an inhaler with them so that they can take a dose in response to an attack. This makes it desirable that the inhaler should be easy and compact to carry. For example some users may wish to be able easily to slip the inhaler into and out of a pocket of their clothing, such as a trouser pocket. The elbowed configuration of a conventional, one-piece moulded, inhaler housing makes the whole unit somewhat cumbersome, awkward to carry about the person and sometimes difficult to slip into a pocket.
Since inhalers are made and sold in large quantities, it is also commercially important to be able to package and transport them in a space-efficient manner. In this respect as well, a one-piece elbowed inhaler housing is less than optimal. Consider for example that if the housing is to be packaged in a cuboidal box, that box must have an increased width to accommodate the laterally protruding mouthpiece.
The prior art includes certain inhalers which are able to be reconfigured for carrying/storage.
U.S. Pat. No. 4,641,644—Andersson et al.—discloses a pocket-size aerosol inhalation device which has a dosage dispensing position and a storage position. The device's mouthpiece is formed by a two-part telescoping deceleration chamber. A socket is provided to receive the inhaler canister. The socket is connected pivotally to an inner part of the telescoping deceleration chamber. In the storage position, the socket is telescopically inserted into an inner part of the deceleration chamber, and the two parts of that chamber are also telescopically collapsed. Disadvantages of this construction include its complexity and the fact that because three different telescoping components must be received one inside another, around the inhaler canister, the lateral dimensions of the collapsed device are unavoidably increased, which does not help in providing a slim and compact device which can easily be slipped into a pocket.
DE3911985—Boehringer Ingelheim KG—discloses an inhaler having a mouthpiece and a cartridge housing which are coupled to one another through a snap fitting which allows one to be rotated relative to the other about an inclined axis. In this way the mouthpiece and the cartridge housing are able to be aligned with one another in one configuration and to form an elbowed or “L” shape in another configuration. No mechanism appears to be provided for positively locating the two parts in the two configurations, however.
U.S. Pat. No. 4,637,528—Wachinski et al.—discloses an aerosol medicament dispenser in which a cylindrical housing for receiving an aerosol container is coupled to a sleeve provided with a mouthpiece through a sliding and pivoting joint. The sleeve is telescopically mounted by engagement of a pair of pin-like projections on a pair of ears formed on the sleeve with slots in opposite side walls of the housing. The sleeve can thus be telescoped into the housing but when drawn out of it can be pivoted to form an “L” shape. The arrangement appears relatively complex and vulnerable to damage or malfunction, which is of course a vital concern since users' health may depend on timely treatment.
WO92/20391—Abbott Laboratories—is somewhat similar to U.S. Pat. No. 4,637,528 in disclosing an inhalation device having a sliding and pivoting joint to couple its two main parts, and similar comments apply.
A need exists for an inhaler housing which can be quickly and easily reconfigured for (a) use and (b) carrying/storage, and which makes it immediately clear to the user whether it is correctly configured for use.